Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 94
Filtrar
Mais filtros

Base de dados
País/Região como assunto
Tipo de documento
Intervalo de ano de publicação
1.
Nat Immunol ; 18(10): 1128-1138, 2017 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-28846085

RESUMO

The transcription factor RORγt regulates differentiation of the TH17 subset of helper T cells, thymic T cell development and lymph-node genesis. Although elimination of RORγt prevents TH17 cell-mediated experimental autoimmune encephalomyelitis (EAE), it also disrupts thymocyte development, which could lead to lethal thymic lymphoma. Here we identified a two-amino-acid substitution in RORγt (RORγtM) that 'preferentially' disrupted TH17 differentiation but not thymocyte development. Mice expressing RORγtM were resistant to EAE associated with defective TH17 differentiation but maintained normal thymocyte development and normal lymph-node genesis, except for Peyer's patches. RORγtM showed less ubiquitination at Lys69 that was selectively required for TH17 differentiation but not T cell development. This study will inform the development of treatments that selectively target TH17 cell-mediated autoimmunity but do not affect thymocyte development or induce lymphoma.


Assuntos
Substituição de Aminoácidos , Diferenciação Celular/genética , Mutação , Membro 3 do Grupo F da Subfamília 1 de Receptores Nucleares/genética , Células Th17/citologia , Células Th17/metabolismo , Timócitos/citologia , Timócitos/metabolismo , Animais , Biomarcadores , Diferenciação Celular/imunologia , Análise por Conglomerados , Encefalomielite Autoimune Experimental/genética , Encefalomielite Autoimune Experimental/imunologia , Encefalomielite Autoimune Experimental/metabolismo , Perfilação da Expressão Gênica , Regulação da Expressão Gênica , Imunofenotipagem , Linfonodos/imunologia , Linfonodos/metabolismo , Camundongos , Camundongos Knockout , Nódulos Linfáticos Agregados/imunologia , Nódulos Linfáticos Agregados/metabolismo , Subpopulações de Linfócitos T/citologia , Subpopulações de Linfócitos T/imunologia , Subpopulações de Linfócitos T/metabolismo , Células Th17/imunologia , Timócitos/imunologia , Ubiquitinação
2.
PLoS Pathog ; 18(3): e1010390, 2022 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-35286345

RESUMO

[This corrects the article DOI: 10.1371/journal.ppat.1004253.].

3.
J Acoust Soc Am ; 156(2): 989-1003, 2024 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-39136635

RESUMO

In order to improve the prediction accuracy of the sound quality of vehicle interior noise, a novel sound quality prediction model was proposed based on the physiological response predicted metrics, i.e., loudness, sharpness, and roughness. First, a human-ear sound transmission model was constructed by combining the outer and middle ear finite element model with the cochlear transmission line model. This model converted external input noise into cochlear basilar membrane response. Second, the physiological perception models of loudness, sharpness, and roughness were constructed by transforming the basilar membrane response into sound perception related to neuronal firing. Finally, taking the calculated loudness, sharpness, and roughness of the physiological model and the subjective evaluation values of vehicle interior noise as the parameters, a sound quality prediction model was constructed by TabNet model. The results demonstrate that the loudness, sharpness, and roughness computed by the human-ear physiological model exhibit a stronger correlation with the subjective evaluation of sound quality annoyance compared to traditional psychoacoustic parameters. Furthermore, the average error percentage of sound quality prediction based on the physiological model is only 3.81%, which is lower than that based on traditional psychoacoustic parameters.


Assuntos
Percepção Sonora , Ruído dos Transportes , Psicoacústica , Humanos , Percepção Sonora/fisiologia , Estimulação Acústica/métodos , Análise de Elementos Finitos , Modelos Biológicos , Automóveis , Membrana Basilar/fisiologia , Cóclea/fisiologia , Percepção Auditiva/fisiologia , Ruído , Orelha Média/fisiologia , Simulação por Computador
4.
Int J Mol Sci ; 25(12)2024 Jun 19.
Artigo em Inglês | MEDLINE | ID: mdl-38928450

RESUMO

Abnormal cell proliferation and growth leading to cancer primarily result from cumulative genome mutations. Single gene mutations alone do not fully explain cancer onset and progression; instead, clustered mutations-simultaneous occurrences of multiple mutations-are considered to be pivotal in cancer development and advancement. These mutations can affect different genes and pathways, resulting in cells undergoing malignant transformation with multiple functional abnormalities. Clustered mutations influence cancer growth rates, metastatic potential, and drug treatment sensitivity. This summary highlights the various types and characteristics of clustered mutations to understand their associations with carcinogenesis and discusses their potential clinical significance in cancer. As a unique mutation type, clustered mutations may involve genomic instability, DNA repair mechanism defects, and environmental exposures, potentially correlating with responsiveness to immunotherapy. Understanding the characteristics and underlying processes of clustered mutations enhances our comprehension of carcinogenesis and cancer progression, providing new diagnostic and therapeutic approaches for cancer.


Assuntos
Carcinogênese , Mutação , Neoplasias , Humanos , Neoplasias/genética , Neoplasias/patologia , Carcinogênese/genética , Instabilidade Genômica , Transformação Celular Neoplásica/genética , Reparo do DNA/genética , Animais
5.
Int J Mol Sci ; 25(3)2024 Jan 26.
Artigo em Inglês | MEDLINE | ID: mdl-38338839

RESUMO

Autophagy, a complex and highly regulated cellular process, is critical for the maintenance of cellular homeostasis by lysosomal degradation of cellular debris, intracellular pathogens, and dysfunctional organelles. It has become an interesting and attractive topic in cancer because of its dual role as a tumor suppressor and cell survival mechanism. As a highly conserved pathway, autophagy is strictly regulated by diverse non-coding RNAs (ncRNAs), ranging from short and flexible miRNAs to lncRNAs and even circRNAs, which largely contribute to autophagy regulatory networks via complex RNA interactions. The potential roles of RNA interactions during autophagy, especially in cancer procession and further anticancer treatment, will aid our understanding of related RNAs in autophagy in tumorigenesis and cancer treatment. Herein, we mainly summarized autophagy-related mRNAs and ncRNAs, also providing RNA-RNA interactions and their potential roles in cancer prognosis, which may deepen our understanding of the relationships between various RNAs during autophagy and provide new insights into autophagy-related therapeutic strategies in personalized medicine.


Assuntos
MicroRNAs , Neoplasias , RNA Longo não Codificante , Humanos , RNA não Traduzido/genética , MicroRNAs/genética , MicroRNAs/metabolismo , Neoplasias/genética , RNA Mensageiro/genética , RNA Longo não Codificante/genética , RNA Longo não Codificante/metabolismo , Autofagia/genética
6.
J Immunol ; 207(1): 23-33, 2021 07 01.
Artigo em Inglês | MEDLINE | ID: mdl-34135062

RESUMO

Th17 cells have emerged as a chief pathogenic cell type in murine models of autoimmunity and human autoimmune diseases. Th17 cells are markedly plastic in their pathogenic potential, as they can adopt pro- or anti-inflammatory programming under distinct conditions. The specific mechanism underlying the plasticity of Th17 pathogenesis remains elusive. In this study, we found that Th17 lineage-specific transcription factor RORγt directly bound to the promoters of genes engaged in the ubiquitination pathway and thus upregulated their expression in pathogenic Th17 cells. We observed that ubiquitination activity correlated with Th17-related pathology in the context of autoimmunity. Consistent with this finding, the deubiquitinase USP19 was shown to suppress pathogenic Th17 differentiation in vitro and Th17-mediated pathogenesis in vivo. Mechanistically, USP19 removed the K63-linked ubiquitin chain from RORγt lysine 313, which is essential for recruiting the coactivator SRC3. Collectively, our findings indicate that USP19 selectively suppresses the pathogenic potential of Th17 cells and offer novel strategies for treating autoimmune diseases.


Assuntos
Doenças Autoimunes , Células Th17 , Animais , Autoimunidade , Diferenciação Celular , Endopeptidases , Regulação da Expressão Gênica , Humanos , Camundongos , Membro 3 do Grupo F da Subfamília 1 de Receptores Nucleares/genética , Membro 3 do Grupo F da Subfamília 1 de Receptores Nucleares/metabolismo , Células Th17/metabolismo
7.
J Immunol ; 202(3): 760-769, 2019 02 01.
Artigo em Inglês | MEDLINE | ID: mdl-30567733

RESUMO

SRC3, a highly conserved member of the steroid receptor coactivator (SRC) family, is recruited by transcription factors to regulate cellular function. Previously, we demonstrated that SRC1, another highly conserved member of the SRC family, interacts with RORγt to regulate Th17 differentiation. However, the relationship between SRC1 and SRC3 in the regulation of Th17 cell function remains unknown. In this study, we demonstrate that mouse SRC3 interacts with RORγt in Th17 cells but not in thymocytes. In addition, Src3-/- mice exhibited defective Th17 differentiation and induction of experimental autoimmune encephalomyelitis but normal thymocyte development. Furthermore, a K313 to arginine mutation of RORγt (RORγt-K313R), which disrupts the interaction of RORγt with SRC3 but not with SRC1, impairs Th17 differentiation but not thymocyte development. These data suggest that SRC3 works with SRC1 to regulate RORγt-dependent Th17 differentiation but is not essential for RORγt-dependent thymocyte development.


Assuntos
Diferenciação Celular , Coativador 3 de Receptor Nuclear/genética , Membro 3 do Grupo F da Subfamília 1 de Receptores Nucleares/genética , Células Th17/imunologia , Timócitos/citologia , Animais , Encefalomielite Autoimune Experimental/imunologia , Regulação da Expressão Gênica , Ativação Linfocitária , Camundongos , Camundongos Knockout , Células Th17/citologia , Timócitos/imunologia
8.
Proc Natl Acad Sci U S A ; 115(3): E458-E467, 2018 01 16.
Artigo em Inglês | MEDLINE | ID: mdl-29282318

RESUMO

Th17 cells are major players in multiple autoimmune diseases and are developmentally contingent on reciprocal functionality between the transcription factor Retineic acid receptor-related orphan nuclear receptor gamma (RORγt) and Forkhead box protein P3 (Foxp3). Here we deciphered a previously unappreciated role of Steroid receptor coactivator 1 (SRC1) in defining the lineage decision for the development of Th17 versus induced T-regulatory (iTreg) cells. We demonstrate that SRC1 functions as a critical coactivator for RORγt in vivo to promote the functional dominance of RORγt over Foxp3 and thus establishing an unopposed Th17 differentiation program. In the absence of SRC1, T cell polarization resulted in decreased IL-17+ and increased Foxp3+ cells during both in vitro differentiation and in vivo development of experimental autoimmune encephalomyelitis. Mechanistically, T cell receptor (TCR) signaling molecule protein kinase C theta (PKC-θ)-mediated phosphorylation of SRC1 is important for inducing enhanced RORγt-SRC1 interaction, stable DNA binding, and resultant IL-17A transcription. Furthermore, phospho-SRC1-mediated recruitment of CARM1 induced prominent asymmetric dimethylation of H3R17 while preventing repressive H3K9 trimethylation and hence further modifying the IL-17 locus for optimal transcription. Moreover, binding of phospho-SRC1 to RORγt displaced bound Foxp3, leading to prompt degradation of the dissociated Foxp3 via a ubiquitin-proteosomal pathway and hence reversing the inhibitory action of Foxp3 on RORγt activity. Thus, SRC1 acts as a crucial molecular mediator to integrate positive PKC-θ-dependent TCR signals to induce peak RORγt activity and establish phenotypic dominance of Th17 over the iTreg pathway.


Assuntos
Diferenciação Celular/fisiologia , Fatores de Transcrição Forkhead/metabolismo , Coativador 1 de Receptor Nuclear/metabolismo , Membro 3 do Grupo F da Subfamília 1 de Receptores Nucleares/metabolismo , Proteína Quinase C-theta/metabolismo , Células Th17/fisiologia , Sequência de Aminoácidos , Animais , Fatores de Transcrição Forkhead/genética , Deleção de Genes , Regulação Enzimológica da Expressão Gênica/fisiologia , Interleucinas/genética , Interleucinas/metabolismo , Camundongos , Coativador 1 de Receptor Nuclear/química , Coativador 1 de Receptor Nuclear/genética , Membro 3 do Grupo F da Subfamília 1 de Receptores Nucleares/genética , Proteína Quinase C-theta/genética
9.
Fish Shellfish Immunol ; 100: 238-245, 2020 May.
Artigo em Inglês | MEDLINE | ID: mdl-32135341

RESUMO

Licorice is a widely used herbal medicine for the treatment of various diseases in southern Europe and parts of Asia. It has been reported that the isoliquiritin (ISL) from Glycyrrhiza root has the activity of promoting angiogenesis. The purpose of this study was to investigate the effect of ISL on the wound healing activity of zebrafish and its mechanism. 6-month-old zebrafish were injured in the skin (2 mm in diameter) and then treated with ISL. By measuring wound size and by histological examination, we found that ISL improved wound healing. In addition, 4-day-old zebrafish embryos of double transgenic line [Tg(fli-1:EGFP)]/[Tg(mpeg:mCherry)] were suffered from tissue traumas and then treated with ISL. Through fluorescent microscopy, we found that ISL promoted macrophage recruitment and angiogenesis in the wound area. Through qPCR analysis, we found that ISL up-regulated the expression of genes related to inflammation and angiogenesis in zebrafish embryos. These results showed that ISL could promote inflammatory response and angiogenesis, which played key roles in promoting wound healing. Therefore, ISL can be used as a promising candidate to promote wound healing.


Assuntos
Chalcona/análogos & derivados , Glucosídeos/farmacologia , Macrófagos/imunologia , Neovascularização Fisiológica/efeitos dos fármacos , Extratos Vegetais/farmacologia , Cicatrização/efeitos dos fármacos , Peixe-Zebra/imunologia , Animais , Chalcona/farmacologia , Inflamação/genética , Plantas Medicinais/química , Pele/efeitos dos fármacos , Pele/lesões , Peixe-Zebra/lesões
10.
J Immunol ; 200(10): 3397-3406, 2018 05 15.
Artigo em Inglês | MEDLINE | ID: mdl-29632143

RESUMO

T cell factor 1 (TCF-1) is expressed in both developing and mature T cells and has been shown to restrain mature T cell-mediated Th17 responses by inhibiting IL-17 expression. However, it is not clear when TCF-1 is required in vivo to restrain the magnitude of peripheral Th17 responses and what the molecular mechanisms responsible for TCF-1-regulated IL-17 gene expression are. In this study, we showed that conditional deletion of TCF-1 at the early but not later CD4+CD8+ double-positive stage in mice enhanced Th17 differentiation and aggravated experimental autoimmune encephalomyelitis, which correlates with abnormally high IL-17 expression. Expression of TCF-1 in TCF-1-deficient thymocytes but not TCF-1-deficient Th17 cells inhibited IL-17 expression. TCF-1 binds to IL-17 promoter regions, and deletion of two TCF-1 binding sites relieves TCF-1-mediated inhibition of IL-17 promoter activity. Lastly, wild-type TCF-1, but not a TCF-1 mutant that has no intrinsic histone deacetylase activity, was able to inhibit IL-17 expression in TCF-1 deficient mouse thymocytes. Thus, our study demonstrates the requirement of TCF-1 in vivo at stages earlier than double-positive cells to restrain peripheral Th17 immunity by directly binding and inhibiting IL-17 promoter in its intrinsic histone deacetylase-dependent manner.


Assuntos
Expressão Gênica/imunologia , Fator 1-alfa Nuclear de Hepatócito/imunologia , Imunidade/genética , Imunidade/imunologia , Interleucina-17/genética , Interleucina-17/imunologia , Células Th17/imunologia , Animais , Linfócitos T CD4-Positivos/imunologia , Linfócitos T CD8-Positivos/imunologia , Diferenciação Celular/genética , Diferenciação Celular/imunologia , Encefalomielite Autoimune Experimental/genética , Encefalomielite Autoimune Experimental/imunologia , Expressão Gênica/genética , Histona Desacetilases/genética , Histona Desacetilases/imunologia , Camundongos , Regiões Promotoras Genéticas/genética , Regiões Promotoras Genéticas/imunologia , Timócitos/imunologia
11.
J Immunol ; 201(2): 440-450, 2018 07 15.
Artigo em Inglês | MEDLINE | ID: mdl-29794014

RESUMO

Th17 cells are a class of Th cells that secrete IL-17 and mediate pathogenic immunity responsible for autoimmunity including experimental autoimmune encephalomyelitis, a murine model of multiple sclerosis. Retinoic acid-related orphan receptor γ t (RORγt) is the critical transcription factor that controls the differentiation of Th17 cells. However, little is known about the transcriptional cofactors for RORγt in the regulation of Th17 differentiation. In this study, we demonstrate that protein arginine N-methyltransferase 1 (PRMT1) associates with RORγt and regulates mouse Th17 differentiation. Overexpression of PRMT1 promoted Th17 differentiation, whereas inactivation or knockdown of PRMT1 decreased Th17 differentiation while expanding Foxp3+ regulatory T cells. Consistently, pharmacological inhibition of PRMT1 impaired the generation of Th17 cells and prevented induction of experimental autoimmune encephalomyelitis in mice. Mechanistically, PRMT1-dependent modification of asymmetric histone 4 arginine 3 dimethylation is required to stabilize the stimulatory STAT3 to displace the inhibitory STAT5 at IL-17 locus, resulting in the activation of IL-17 gene. Furthermore, PRMT1-facilitated recruitment of STAT3 overcame the inhibition of Th17 differentiation exerted by IL-2-induced STAT5 activation. PRMT1 thus regulates Th17 differentiation by controlling the reciprocal recruitment of STAT3 and STAT5. Our study thus reveals PRMT1 as a novel target for alleviating Th17-mediated autoimmunity by decreasing RORγt-dependent generation of pathogenic Th17 cells.


Assuntos
Diferenciação Celular/imunologia , Encefalomielite Autoimune Experimental/imunologia , Encefalomielite Autoimune Experimental/metabolismo , Proteína-Arginina N-Metiltransferases/metabolismo , Fator de Transcrição STAT3/metabolismo , Fator de Transcrição STAT5/metabolismo , Células Th17/metabolismo , Animais , Autoimunidade/imunologia , Interleucina-17/imunologia , Camundongos , Camundongos Endogâmicos C57BL , Receptores do Ácido Retinoico/metabolismo , Células Th17/imunologia , Receptor gama de Ácido Retinoico
12.
Fam Pract ; 37(4): 525-529, 2020 09 05.
Artigo em Inglês | MEDLINE | ID: mdl-32112080

RESUMO

BACKGROUND: Inter-clinician electronic consultation (eConsult) programmes are becoming more widespread in the USA as health care systems seek innovative ways of improving specialty access. Existing studies examine models with programmatic incentives or requirements for primary care providers (PCPs) to participate. OBJECTIVE: We aimed to examine PCP perspectives on eConsults in a system with no programmatic incentive or requirement for PCPs to use eConsults. METHODS: We conducted seven focus groups with 41 PCPs at a safety-net community teaching health care system in Eastern Massachusetts, USA. RESULTS: Focus groups revealed that eConsults improved PCP experience by enabling patient-centred care and enhanced PCP education. However, increased workload and variations in communication patterns added challenges for PCPs. Patients were perceived as receiving timelier and more convenient care. Timelier care combined with direct documentation in the patient record was perceived as improving patient safety. Although cost implications were less clear, PCPs perceived costs as being lowered through fewer unnecessary visits and laboratories. CONCLUSIONS: Our findings suggest that eConsult systems with no programmatic incentives or requirements for PCPs have the potential to improve care.


Assuntos
Medicina , Motivação , Pessoal de Saúde , Humanos , Atenção Primária à Saúde , Encaminhamento e Consulta
13.
Sensors (Basel) ; 20(12)2020 Jun 17.
Artigo em Inglês | MEDLINE | ID: mdl-32560453

RESUMO

To allow mobile robots to visually observe the temperature of equipment in complex industrial environments and work on temperature anomalies in time, it is necessary to accurately find the coordinates of temperature anomalies and obtain information on the surrounding obstacles. This paper proposes a visual saliency detection method for hypertemperature in three-dimensional space through dual-source images. The key novelty of this method is that it can achieve accurate salient object detection without relying on high-performance hardware equipment. First, the redundant point clouds are removed through adaptive sampling to reduce the computational memory. Second, the original images are merged with infrared images and the dense point clouds are surface-mapped to visually display the temperature of the reconstructed surface and use infrared imaging characteristics to detect the plane coordinates of temperature anomalies. Finally, transformation mapping is coordinated according to the pose relationship to obtain the spatial position. Experimental results show that this method not only displays the temperature of the device directly but also accurately obtains the spatial coordinates of the heat source without relying on a high-performance computing platform.

14.
J Immunol ; 199(3): 955-964, 2017 08 01.
Artigo em Inglês | MEDLINE | ID: mdl-28667162

RESUMO

Transcription factor retinoid acid-related orphan receptor (ROR)γt transcriptionally regulates the genes required for differentiation of Th17 cells that mediate both protective and pathogenic immunity. However, little is known about the function of posttranslational modifications in the regulation of RORγt activity. Mass spectrometric analysis of immunoprecipitated RORγt from Th17 cells identified multiple phosphorylation sites. Systematic mutation analysis of the identified phosphorylation sites found that phosphorylation of S376 enhances whereas phosphorylation of S484 inhibits Th17 differentiation. IκB kinase (IKK)α binds and phosphorylates RORγt at S376 but not S484. Knockdown of IKKα, dominant-negative IKKα, and RORγt mutants incapable of interacting with IKKα all decrease Th17 differentiation. Furthermore, nonphosophorylatable RORγt mutant (S376A) impairs whereas phosphomimetic mutant (S376E) stimulates Th17 differentiation independent of IKKα. Therefore, IKKα-dependent phosphorylation of S376 stimulated whereas IKKα-independent phosphorylation of S484 inhibited RORγt function in Th17 differentiation.


Assuntos
Quinase I-kappa B/metabolismo , Membro 3 do Grupo F da Subfamília 1 de Receptores Nucleares/metabolismo , Células Th17/imunologia , Animais , Diferenciação Celular , Regulação da Expressão Gênica/imunologia , Regulação da Expressão Gênica/fisiologia , Células HEK293 , Humanos , Quinase I-kappa B/deficiência , Quinase I-kappa B/genética , Espectrometria de Massas , Camundongos , Mutação , Membro 3 do Grupo F da Subfamília 1 de Receptores Nucleares/química , Membro 3 do Grupo F da Subfamília 1 de Receptores Nucleares/genética , Membro 3 do Grupo F da Subfamília 1 de Receptores Nucleares/imunologia , Fosforilação , Células Th17/fisiologia
15.
PLoS Pathog ; 12(10): e1005900, 2016 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-27760204

RESUMO

Kaposi's sarcoma (KS)-associated herpesvirus (KSHV) is an oncogenic pathogen that displays latent and lytic life cycles. In KS lesions, infiltrated immune cells, secreted viral and/or cellular cytokines, and hypoxia orchestrate a chronic pro-lytic microenvironment that can promote KSHV reactivation. However, only a small subset of viruses spontaneously undergoes lytic replication in this pro-lytic microenvironment while the majority remains in latency. Here, we show that the expression of the Notch ligand JAG1 is induced by KSHV-encoded replication and transcription activator (RTA) during reactivation. JAG1 up-regulation activates Notch signaling in neighboring cells and prevents viral lytic replication. The suppression of JAG1 and Notch1 with inhibitors or small interfering RNA promotes lytic replication in the presence of RTA induction or under conditions of hypoxia. The underlying mechanism involves the Notch downstream effector hairy and enhancer of split 1 (Hes1), which directly binds lytic gene promoters and attenuates viral lytic gene expression. RTA interacts with lymphoid enhancer-binding factor 1 (LEF1), disrupts LEF1/Groucho/TLE suppressive complexes and releases LEF1 to activate JAG1 expression. Taken together, our results suggest that cells with viral lytic replication can inhibit KSHV reactivation in neighboring cells through an RTA-JAG1-Notch pathway. These data provide insight into the mechanism by which the virus maintains the balance between lytic and latent infection in the pro-lytic tumor microenvironment.


Assuntos
Herpesvirus Humano 8/fisiologia , Proteínas Imediatamente Precoces/metabolismo , Proteína Jagged-1/metabolismo , Receptores Notch/metabolismo , Transativadores/metabolismo , Latência Viral/fisiologia , Western Blotting , Linhagem Celular , Imunoprecipitação da Cromatina , Técnicas de Cocultura , Citometria de Fluxo , Imunofluorescência , Humanos , Reação em Cadeia da Polimerase em Tempo Real , Sarcoma de Kaposi/virologia , Transdução de Sinais/fisiologia , Transfecção , Ativação Viral/fisiologia
16.
J Immunol ; 197(4): 1148-58, 2016 08 15.
Artigo em Inglês | MEDLINE | ID: mdl-27430721

RESUMO

The transcription factor retinoid acid-related orphan receptor γ t (RORγt) directs the differentiation of Th17 cells. Th17 cells mediate pathological immune responses responsible for autoimmune diseases, including psoriasis and multiple sclerosis. Previous studies focused on RORγt target genes and their function in Th17 differentiation. In this study, we assessed posttranscriptional regulation of RORγt and identified a functional ubiquitination site, K446. Mutation of K446 to arginine to prevent ubiquitination greatly enhanced recruitment of steroid receptor coactivator 1 (SRC1), a coactivator critical for RORγt activity. Correspondingly, the K446 to arginine mutation potentiated Th17 differentiation. We also showed that ubiquitin-specific protease (USP)15 interacted with RORγt, removed ubiquitin from K446, and stimulated RORγt activity by enhancing coactivator SRC1 recruitment. Knockdown of USP15 or expression of inactive USP15 impaired Th17 differentiation, suggesting a positive role for USP15-mediated deubiquitination of RORγt in Th17 differentiation. Therefore, ubiquitination of K446 limits RORγt-mediated Th17 differentiation by inhibiting the recruitment of coactivator SRC1. Our study will inform the development of treatments that target RORγt ubiquitination pathways to limit Th17-mediated autoimmunity.


Assuntos
Coativador 1 de Receptor Nuclear/metabolismo , Membro 3 do Grupo F da Subfamília 1 de Receptores Nucleares/metabolismo , Células Th17/imunologia , Animais , Diferenciação Celular/imunologia , Citometria de Fluxo , Imunoprecipitação , Lisina/metabolismo , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Reação em Cadeia da Polimerase , Células Th17/citologia , Células Th17/metabolismo , Ubiquitinação
17.
PLoS Pathog ; 10(7): e1004253, 2014 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-25010525

RESUMO

Kaposi's sarcoma-associated herpesvirus (KSHV) is the etiological agent of Kaposi's sarcoma (KS), a malignancy commonly found in AIDS patients. Whether KS is a true neoplasm or hyperplasia has been a subject of intensive debate until recently when KSHV is unequivocally shown to efficiently infect, immortalize and transform rat primary mesenchymal precursor cells (MM). Moreover, KSHV-transformed MM cells (KMM) efficiently induce tumors with hallmark features of KS when inoculated into nude mice. Here, we showed Smad1 as a novel binding protein of KSHV latency-associated nuclear antigen (LANA). LANA interacted with and sustained BMP-activated p-Smad1 in the nucleus and enhanced its loading on the Id promoters. As a result, Ids were significantly up-regulated in KMM cells and abundantly expressed in human KS lesions. Strikingly, genetic and chemical inhibition of the BMP-Smad1-Id pathway blocked the oncogenic phenotype of KSHV-transformed cells in vitro and in vivo. These findings illustrate a novel mechanism by which a tumor virus hijacks and converts a developmental pathway into an indispensable oncogenic pathway for tumorigenesis. Importantly, our results demonstrate the efficacy of targeting the BMP-Smad1-Id pathway for inhibiting the growth of KSHV-induced tumors, and therefore identify the BMP pathway as a promising therapeutic target for KS.


Assuntos
Proteínas Morfogenéticas Ósseas/metabolismo , Transformação Celular Viral , Herpesvirus Humano 8/metabolismo , Proteína 1 Inibidora de Diferenciação/metabolismo , Transdução de Sinais , Proteína Smad1/metabolismo , Animais , Antígenos Virais , Linhagem Celular Transformada , Feminino , Xenoenxertos , Células Endoteliais da Veia Umbilical Humana , Humanos , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Nus , Transplante de Neoplasias , Proteínas Nucleares , Ratos , Sarcoma de Kaposi/metabolismo
18.
Clin Endocrinol (Oxf) ; 84(1): 3-12, 2016 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-26118628

RESUMO

Radioactive iodine (RAI) ablation is a beneficial, adjuvant therapy for the management of differentiated thyroid cancer (DTC) after thyroidectomy. The goal of RAI is to destroy remnant thyroid and microscopic cancerous tissue. Radioactive iodine uptake is enhanced by elevating TSH levels and initiating a low iodine diet (LID) prior to ablation. An ideal LID should preferably not exceed 50 mcg/day of dietary iodine for 1-2 weeks, although the duration may be shortened to a week with a structured patient education programme. A pre-ablation spot urinary iodine concentration (UIC) of <100 mcg/l and/or a urinary iodine to creatinine ratio (UICR) of <100 mcg/gCr would support an adequate LID preparation. Hyponatraemia, most likely due to iatrogenic hypothyroidism, is a potential side effect associated with LID and occurs during and a few days after the LID. Although the overall incidence of hyponatraemia is low, patients at high risk (older age, female sex, use of thiazide diuretics) may benefit from serum sodium monitoring. The existing evidence on the impact of LID on RAI ablation has been largely inconsistent due to retrospective study designs and the lack of an objective measurement of urinary iodine levels. Future large prospective randomized control trials are needed to elucidate and confirm the crucial role of LID in achieving successful RAI ablation and greater disease-free survival in DTC.


Assuntos
Dieta , Radioisótopos do Iodo/uso terapêutico , Iodo/administração & dosagem , Neoplasias da Glândula Tireoide/dietoterapia , Neoplasias da Glândula Tireoide/radioterapia , Terapia Combinada , Humanos , Iodo/urina , Guias de Prática Clínica como Assunto , Fatores de Risco , Neoplasias da Glândula Tireoide/cirurgia , Tireoidectomia , Resultado do Tratamento
20.
Int J Toxicol ; 35(6): 712-718, 2016 11.
Artigo em Inglês | MEDLINE | ID: mdl-27694306

RESUMO

With the increasing use of mycophenolic acid (MPA) in solid organ transplantation, some clinical studies indicate that it is also a human teratogen. However, it is unknown by which mechanism MPA acts as a teratogen. Mycophenolic acid was a selective blocker of de novo purine synthesis, and its immunosuppressive effect is mediated by the inhibition of inosine monophosphate dehydrogenase, which could be a target for MPA-induced toxicity as well. The aim of our study was to examine the direct influence of MPA exposure on zebrafish (Danio rerio) embryos. Morphological defects including tail curvature and severe pericardial edema in zebrafish embryos caused by MPA (3.7-11.1 µmol/L) were found in a dose-dependent manner. The teratogenic index (25% lethal concentration value (LC25)/no observed adverse effect level ratio) was 16, which indicated MPA as a teratogen. Quantitative polymerase chain reaction analysis revealed that the expression level of impdh1b and impdh2 was significantly reduced by MPA treatment at 8 µmol/L (equals to LC25 level). All the toxic effects could be partially reversed by the addition of 33.3 µmol/L guanosine. Our results indicated that MPA impairs the development of zebrafish embryos via inhibition of impdh activity, which subsequently caused a guanosine nucleotide depletion in vivo.


Assuntos
IMP Desidrogenase/antagonistas & inibidores , Imunossupressores/toxicidade , Ácido Micofenólico/toxicidade , Teratogênicos/toxicidade , Animais , Embrião não Mamífero , Desenvolvimento Embrionário/efeitos dos fármacos , Regulação Enzimológica da Expressão Gênica/efeitos dos fármacos , Guanosina/farmacologia , IMP Desidrogenase/genética , Dose Letal Mediana , Nível de Efeito Adverso não Observado , Cauda/anormalidades , Peixe-Zebra
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA